JZA70 Clutch Problems

[Shadow6]

So i bought another JZA70 about 8 months back, already had the big single, E-Managment, SABC and Manual conversion...

Well the clutch kinda let go about 5 months ago... turns out i needed a stronger clutch. Possibly the fault of low quality slave and master cylinders i dont know, i was just told they need replacing. so i ordered from the states (what i have found out was the wrong part)

http://www.clutchcityonline.com/toyota_supra.htm
M1661 $75.86 1 New Toyota Master Cylinder Assmebly
S1663 $44.73 1 New Toyota Slave Cylinder Assmebly

either way the Mechanic fitted them along with a heavy duty clutch...

well the day before i was to drive to Brissy 4 Christmas something went wrong. there was a "bumpy" feeling on the clutch pedal whilst driving and the pedal needed to be released further and further back before the clutch would let go. if i accelerate anymore then a sunday driver the clutch seems to re-engage with-out even touching the pedal.

WHATS GOING ON!!!

the mechanic has now said that they have taken almost an inch off the slave and its slill not working. seems to get worse as she heats up they recon. they are also asking if there should be a dampener for the clutch when it was converted too.

any ideas ppl?? can i help with any more info??

Thanks.

[Shadow6]

Well i just picked up the "car"...

they are saying the shaft in the slave was too long and have replaced it with a shorter shaft (stud). they say the clutch is fine but it looks as if the master cylinder could be the problem. The pressure in the line is not releasing once the clutch is released. replace master??

[lexsmaz]

At a guess i would say that they have not given enough clearance for the pushod to the master clinder .. Which is stopping the master cylinder from returning to its rest position & keeping residual pressure in the line ..

[Shadow6]

The weird thing is that it worked fine for those few months. would it still be the push rod?

[wilbo666]

Yep, sounds like an issue with the adjustment at the clutch master end...

Personally I'd re-fit a stock length slave push rod, and adjust the pedal at the clutch master end....

And only touch the salve end if needed (which I suspect it isn't if it was working before).



Cheers
Wilbo

[Shadow6]

yeah that was my theory. problem is these retards charged me $250 to look at the car, not fix it and put that shaft in there. does any one know where i can get a new master cylinder cheap? could this have done any damage to the clutch??

[renxun]

i faced the same problem with you before...

when it get heats up , the pedal felt higher and higher and getting hard... i did everything like changing kits and so on .. only to find out that...

the fluid is not returning 100% when your pedal is released. when heated up it gets worst...
take out your master and you will notice the clip that hold your rod that pushes the piston is slightly pushing the piston hence oil failed to return 100%... it can be the piston curve is not deep enough... but a slight grind on the push rod and let it have some small free play willl solve the issue.... im unaware of this at all as most of the time when we install the circlip we just push the whole thing in to fit it...

it should have a very small free play... at least it should 100% retracted when the pedal is released.

long run it can damage the clutch for sure

* just an extra elaboration on what lexsmaz is mentioning

[Shadow6]

Thanks guys!

is it weird that this has only happened now and not 5 months ago when i had it 1st installed??

So if i fumble around, having never really looked at a master cylinder before, be able to do this myself? without damaging anything? is there anything i need to be weary of in pulling it out or grinding it down? how much should i take off??

[Jt_70R]

I dont know if they have them in WA, but if you need a new master/slave cyl, head down to PBR and get your existing units resleeved.
The resleeved units are actually better than a new item from toyota, they resleave the bore with stainless steel tube which is superior to the stock machined casting.

I got my slave master reco'ed a while back for around the 140 mark, drive in drive out.

[renxun]

Thanks guys!

is it weird that this has only happened now and not 5 months ago when i had it 1st installed??

So if i fumble around, having never really looked at a master cylinder before, be able to do this myself? without damaging anything? is there anything i need to be weary of in pulling it out or grinding it down? how much should i take off??

yupe . u can do it yourself without much issue. for the past 5 months maybe its clean.... 5 months later there might be dust, that might stuck it a little bit.... you might need to change the kit inside which consist of piston and seal.... very cheap thou.

if it happen that you need to grind it down... just grind till it have some clearance between a fully returned piston and your rod. thats all

[renxun]

AND also pls dun forget... the INCH that your mechanic took away frm the slave need to be put back

[wilbo666]

You can adjust the pedal at the master cylinder end... there is a small threaded rod with lock nut configuration

Cheers
Wilbo

[Shadow6]

guess i am going to be buying a grinder tomorrow
Crosser fingers, god i hope this works.

oh is there a dampener on the clutch line normally?? if so what does it look like and could that be a cause too??

[wilbo666]

oh is there a dampener on the clutch line normally?? if so what does it look like and could that be a cause too??

No.

PS, what do you need the grinder for?



Cheers
Wilbo

[Shadow6]

yupe .
if it happen that you need to grind it down... just grind till it have some clearance between a fully returned piston and your rod. thats all

thats y repco quoted 18 dollars for a service kit. if that doesnt work, grind her a little i guess